Sumo Digital’s well-received racing title Sonic & All-Stars Racing Transformed got ported to the PC earlier this year. Getting friends in on the action can be troublesome at times, but you can give them an extra nudge with a “Multiplayer Madness” deal going on at GMG. Right now 4-packs of co-op friendly games are heavily discounted. (Other notable titles include Chivalry: Medieval Warfare,Sanctum 2, and Awesomenauts.)

Thanks to the sale, buying four copies of Sonic & All-Stars Racing Transformed sets you back only $12. Until this Friday at 11AM Eastern, all titles listed below are on sale in packs of 4, with the deal available in Europe and the UK as well. You can even get an additional 20% off with coupon code GMG20-4B9NY-L4FEN.

For extra clarification, you’ll be receiving FOUR individual Steam keys for the games you buy in your GMG account. These are not Steam gift codes, so if you don’t have friends who are interested in the games, you can always trade or sell the keys as you see fit.

On the Steam Weekly Sale front, the Steam Midweek Deal brings us Resident Evil: Revelations at 50% off – only $24.99 for the game, and DLCs are on sale at 50% off as well. Before you get your hopes up, the whole Resident Evil franchise isn’t on sale – only Revelations – so you’ll have to wait on RE5 and RE6 for a little bit longer. (In my opinion, Revelations is a much stronger RE game anyway.)

At $25, this deal makes the cheapest price we’ve seen. Revelations is usually around the $33 mark, with the previous lowest price at $26.80 just a month ago. Revelations now also has Steam collectible trading cards added to the system, so it’s complimenting the Midweek Sale nicely. This 50% off deal will end tomorrow Thursday at 1PM Eastern / 10AM Pacific.

If you like to keep your wallet fat, check in every Wednesday and Saturday at 11AM Pacific for the latest deals, brought to you by the crew at Dealzon. We’re here to help Siliconera readers find the best gaming deals online, whether for the PC or console. To be clear, Siliconera will sometimes make money if you buy a game. Feedback? Let us know in the comments.